Shaft alignment tools and methods

ABSTRACT

The present disclosure is directed to a shaft alignment tool including a base, a rotational body mounted on the base for relative rotation with respect to the base, and an alignment meter coupled to the rotational body.

TECHNICAL FIELD

The present disclosure relates generally to a shaft alignment, and moreparticularly to shaft alignment tools and methods.

BACKGROUND

Shaft alignment is an important procedure to ensure proper operation ofmechanical systems including rotational components. For example, aturbine engine system requires shaft alignment between a turbine engineand a gearbox, before they are coupled to provide power transmission.The alignment between shafts generally includes a radial alignment toensure the rotational axes of the shafts are properly positioned withrespect to each other. Existing alignment techniques involve rotatingand handling of shafts themselves, which is cumbersome and dangerous andcan cause damage to the shafts and components mounted thereon.

U.S. Patent Application Publication No. 2010/0226770 to Frick describesan alignment device for aligning adjacent casing sections in a gasturbine engine. The alignment device includes a fixed portion to beattached to a first turbine engine casing and a bridge portion or acradle portion to interface with a second turbine engine casing. Wheninstalled between the first and second turbine engine casings, thebridge portion limits a relative motion between the casings. Analignment between the adjacent casings is performed by moving adjustablecomponents of the alignment device within their range of motion.Fasteners are applied and tightened to lock the adjacent casings intoplace after the alignment.

SUMMARY

Embodiments of the present disclosure are directed to a shaft alignmenttool including a base, a rotational body mounted on the base forrelative rotation with respect to the base, and an alignment metercoupled to the rotational body.

According to another embodiment, the present disclosure provides amethod of aligning a first shaft and a second shaft using a shaftalignment tool having a base and a rotational body mounted on the basefor relative rotation with respect to the base. The method includescoupling the shaft alignment tool to the first shaft, aligning the shaftalignment tool with respect to the first shaft, and rotating therotational body. The method further includes performing a radialalignment between the first shaft and a second shaft based on therotating of the rotational body.

According to yet another embodiment, the present disclosure provides ashaft alignment tool including a base having a base shaft extendingnormal from a base back portion, a rotational body mounted on the baseshaft for relative rotation with respect to the base, and at least onearm extending from the rotational body. The shaft alignment tool furtherincludes an alignment meter coupled to the at least one arm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an exemplary disclosed high-speedcoupling device connecting a turbine engine output shaft and a gearboxinput shaft;

FIG. 2 is a perspective view of an exemplary shaft alignment tool;

FIG. 3 is a cross-sectional view of the alignment tool of FIG. 2;

FIG. 4 is a perspective view of another exemplary shaft alignment tool;

FIG. 5 is a cross-sectional view of the alignment tool of FIG. 4;

FIG. 6 is a flow diagram of an exemplary alignment procedure using thealignment tool of FIGS. 2 and 3; and

FIG. 7 is a flow diagram of another exemplary alignment procedure usingthe alignment tool of FIGS. 4 and 5.

DETAILED DESCRIPTION

FIG. 1 illustrates a high-speed coupling device 30 for connecting aninput shaft 102 disposed within a gearbox housing 126 and an outputshaft 104 disposed within a turbine engine housing 128. Coupling device30 includes a first end unit 106 coupled to input shaft 102, a secondend unit 108 coupled to output shaft 104, and a spacer 110 connectingfirst end unit 106 and second end unit 108. End unit 106 includes ashaft connector 112 and a coupling hub 114, while end unit 108 includesa shaft connector 116 and coupling hub 118. During engine operation,power and torque are transmitted from output shaft 104 to input shaft102 through coupling device 30.

Before spacer 110 is installed to connect end units 106 and 108, shafts102 and 104 need to be properly aligned. In particular, shafts 102 and104 need to be aligned in the radial direction (e.g., radial alignment).Radial alignment ensures shafts 102 and 104 are positioned substantiallyco-axially. The radial alignment may also take into consideration heatexpansion of engine components during normal operation.

FIGS. 2-5 depict exemplary disclosed alignment tools for aligning shafts102 and 104 of FIG. 1. The alignment tools disclosed herein may be usedto align shafts 102 and 104 before end units 106 and 108 are mounted tothe shafts. Specifically, the alignment tool depicted in FIGS. 2 and 3may be mounted across a bore disposed on gearbox housing 126 and/orturbine engine housing 128, while the alignment tool depicted in FIGS. 4and 5 may be attached directly to opposite end faces of shafts 102 and104, for aligning shafts 102 and 104.

Alternatively, the alignment tools disclosed herein may be used to alignshafts 102 and 104 after end units 106 and 108 are mounted.Specifically, the alignment tool depicted in FIGS. 2 and 3 may bemounted across an opening bore of coupling hubs 114 and 118, while thealignment tool depicted in FIGS. 4 and 5 may be mounted on end faces ofshaft connectors 112 and 116, for aligning shafts 102 and 104.

FIGS. 2 and 3 illustrates an exemplary disclosed shaft alignment tool100 according to one embodiment. Alignment tool 100 may be used to alignshaft 104 with opposite shaft 102 depicted in FIG. 1. As shown in FIG.2, alignment tool 100 is attached to a front face 23 of shaft housing 8across bore 24. As discussed above, alignment tool 100 may be used afterend units 106 and 108 are installed on shafts 102 and 104. As such,shaft housing 8 may be part of coupling hub 114 or 118, and shaft 9 mayinclude shaft connector 112 or 116, as shown in FIG. 1, installedthereon. Alternatively, alignment tool 100 may be used before end units106 and 108 are installed on shafts 102 and 104. As such, shaft housing8 may be part of housing 126 or 128, and shaft 9 may be shaft 102 or104, as shown in FIG. 1. Still alternatively, shaft housing 8 may be aportion of a turbine engine assembly, a gear box assembly, a powergenerator assembly, or any other shaft housing associated with amechanical and/or industrial system.

Alignment tool 100 includes a center hub 1 and a plurality of adjustablearms 2. Center hub 1 may have a disc shape, a cylindrical shape, a brickshape, or any other shape that is suitable to provide sufficient supportfor connecting adjustable arms 2. Center hub 1 has a front side 16 and aback side 17. When installed on shaft housing 8, front side 16 facesaway from shaft 9, while back side 17 faces towards shaft 9. A pluralityof slots 18 are formed on front side 16 of center hub 1. Each slot 18 isaligned with one of a plurality of grooves 19 formed on back side 17 ofcenter hub 1. Grooves 19 may be formed on back side 17 of center hub 1along a radial direction. In addition, center hub 1 has one or moregrooves 22 formed on front side 16. Groove or grooves 22 may be formedalong a radial direction or a lateral direction.

Each adjustable arm 2 includes an elongated body having a square orother appropriate cross section, such as a circular cross section. Eachadjustable arm 2 also includes a first end section 25 inserted intogroove 19 of center hub 1 and a second end section 26 extending out fromcenter hub 1. Adjustable arm 2 can slide within groove 19. Whenalignment tool 100 is mounted on shaft housing 8 for performing analignment procedure, the length of second section 26 extending out fromcenter hub 1 can be adjusted according to a diameter of bore 24 bymoving the adjustable arms 2 in or out within groove 19. For example, alarge diameter of bore 24 may require urging adjustable arm 2 radiallyout to increase the length of second end section 26. A small diameter ofbore 24 may require urging adjustable arm 2 radially in to decrease thelength of the second end section 26.

Referring to FIG. 3, a screw hole 20 is formed on a side wall of firstend section 25 of each adjustable arm 2. When adjustable arm 2 ispositioned in groove 19, screw hole 20 on each adjustable arm 2 isaligned along slot 18 on front side 16 of center hub 1. Adjustable arm 2is secured to center hub 1 by a bolt 5 passing through slot 18 andreceived by screw hole 20.

Second end section 26 of each adjustable arm 2 has a first rollerassembly 3 and a second roller assembly 12 mounted thereon. First rollerassembly 3 is secured by a bolt 4 to an end face of second end section26 of adjustable arm 2, while second roller assembly 12 is secured by abolt 14 to a back side of the body of adjustable arm 2. In oneembodiment, first roller assembly 3 and second roller assembly 12 arearranged such that their rotational axes are normal to each other.

Roller assemblies 3 and 12 may have substantially similar structures. Inone exemplary embodiment, each roller assembly (3 and 12) may include abearing 15 mounted on blots 4 and 14. Bearing 15 is secured to secondend section 26 of adjustable arm 2 so that an outer ring 27 of bearing15 can rotate with respect to an inner race 28 of the bearing 15 that isstationary with respect to the adjustable arm 2. Bearing 15 may be aball or roller bearing, or any other type of bearing. Roller assemblies3 and 12 may also include an additional component secured about theouter diameter of outer ring 27.

A magnetic component made of a magnetic material, such as iron, nickel,magnetite, or cobalt may be included at second end section 26 ofadjustable arm 2, for example, at roller assemblies 3 and/or 12. Themagnetic component provides a magnetic force for attaching adjustablearms 2 onto shaft housing 8 and prevents alignment tool 100 from beingeasily detached during an alignment procedure. As shown in FIG. 3, inone embodiment, a magnetic component 29 may be attached to rollerassemblies 3, 12 and secured by bolts 4, 14. Magnetic component 29 maybe associated with both or only one of roller assemblies 3 and 12 oneach adjustable arm 2, or may be separate from one or both rollerassembly 3 and 12, such as being fixedly secured to a portion of theadjustable arm 2 itself Alternatively, the bearings 15 and/or bolts 4and 14 themselves may be made of magnetic material and provide themagnetic force for attaching alignment tool 100 to shaft housing 8.

When adjustable arms 2 are properly adjusted according to the diameterof bore 24, roller assembly 3 abuts front surface 23 of shaft housing 8,while roller assembly 12 abuts bore 24. Alignment tool 100 may berotated by rolling roller assemblies 3 and 12 on front surface 23 andbore surface 24.

Referring to FIG. 3, alignment tool 100 further includes one or moremounting elements, such as rods 6, inserted in respective grooves 22 onthe front side of center hub 1 and secured by bolts 7. Bolts 7 aretightened into respective screw holes formed on the front side of centerhub 1. The screw holes are proximate to groove 22 so that a portion ofthe bolt head of bolt 7 (or a washer associated therewith) clamps rod 6against groove 22 to fix the position of rod 6 when bolt 7 is fullytightened. An alignment meter 10, 11 may be mounted onto rod or rods 6for conducting a shaft alignment. The alignment procedure will bedescribed below.

As shown in FIG. 3, alignment tool 100 may include a self-adjustmentmechanism for automatically adjusting the length of second end section26 of adjustable arm 2 according to the diameter of bore 24.Specifically, the self-adjustment mechanism includes a spring 35disposed between an end face of first end section 25 of adjustable arm 2and center hub 1. More specifically, a hole 21 may be formed in the endface of first end section 25 of adjustable arm 2, while a hole 31 may beformed on an end face of groove 19. Holes 21 and 31 are aligned, therebyforming a cavity. Spring 35 is disposed within the cavity formed byholes 21 and 31 and is loaded when adjustable arm 2 slides into groove19. When alignment tool 100 is mounted on shaft housing 8, spring 9urges adjustable arm 2 outwards and away from center hub 1, therebypressing roller assembly 12 against bore 24. Due to the self-adjustmentmechanism, alignment tool 100 may automatically adapt to the diameter ofbore 24 and does not require precise manual adjustments and measurementsto match the dimension of alignment tool 100 to the diameter of bore 24.

The outward force generated by spring 35 attaches roller assembly 12onto bore 24 and assists in preventing alignment tool 100 from beingdetached from shaft housing 8. In addition, the outward force generatedby spring 35 provides friction between roller assembly 12 and bore 24 soas to assist in maintaining alignment tool 100 oriented during thealignment procedure. In addition, the spring force urges the rollerassemblies 12 to closely follow the surface of bore 24. As a result,variations of the surface contours are reflected in the rotation ofalignment tool 100 through roller assemblies 12.

The self-adjustment mechanism described above may be implemented in eachadjustable arm 2 so that each adjustable arm 2 may automatically adjustthe length of second end section 26 according to the diameter of bore24. Alternatively, the self-adjustment mechanism may be implemented inless than all of the plurality of adjustable arms 2. As a result, onlythe selected one or more of adjustable arms 2 may be automaticallyadjusted. The other adjustable arms 2 may be manually adjusted and fixedin position by bolt 5 or in any other appropriate manner. It is alsocontemplated that one or more adjustable arms 2 may not be adjustable atall, but rather fixedly secured to center hub 1.

The number of adjustable arms 2 may be varied depending on specificapplications. Although FIG. 3 shows three adjustable arms 2, one skilledin the art will recognize that the number of adjustable arms 2 may begreater or fewer than three. For example, alignment tool 100 may includetwo adjustable arms 2 extending from center hub 1 along opposite radialdirections. Alternatively, alignment tool 100 may include four or moreadjustable arms 2 having a similar configuration as that shown in FIGS.2 and 3.

The magnetic force provided by above-described magnetic component 29 mayfurther assist the positioning of alignment tool 100 during thealignment procedure. Because of the magnetic force provided by magneticcomponent 29, alignment tool 100 may be urged against shaft housing 8when the rotational force is removed. In addition, the magnetic forceurges the roller assemblies 3 and 12 to closely follow the surfacecontours of front face 23 and bore 24. As a result, variations of thesurface contours are reflected in the rotation of alignment tool 100through roller assemblies 3 and 12.

FIGS. 4 and 5 illustrate another shaft alignment tool 200 for aligningshafts 102 and 104 of FIG. 1. Depending on whether shaft connectors 112and 116 are installed on shafts 102 and 104, alignment tool 200 may beattached to an end face of the shaft or the shaft connector shown inFIG. 1. For example, alignment tool 200 may be mounted to an end face ofshaft 102 or 104 and used to align shafts 102 and 104 before shaftconnectors 112 and 116 are installed. Alternatively, alignment tool 200may be mounted to an end face of shaft connector 112 or 116 and used toalign shafts 102 and 104 after shaft connectors 112 and 116 areinstalled. Thus, shaft 229 depicted in FIGS. 4 and 5 may be any rotatingpart or component mounted thereon that need to be axially aligned.

Alignment tool 200 includes a base 221, a center hub or a rotationalbody 222, and a front cover 223. Base 221 includes a front side 240 anda back side 241. When alignment tool 200 is mounted onto shaft 229,front side 240 faces away from shaft 229, while back side 241 facestowards shaft 229. Base 221 further includes a shaft 238 formed atsubstantially the center of front side 240 and protruding axiallytherefrom.

Rotational body 222 is mounted onto shaft 238 through bearings 232 and236. Bearings 232 and 236 may be ball or roller bearings or any otherappropriate bearings. A spacer 233 is disposed between bearings 232 and236 to secure an axial distance between bearings 232 and 236.

Front cover 223 is mounted to an end face of shaft 238 by a bolt 224.Front cover 223 has a hole 244 for passing through bolt 224. The endface of shaft 238 has a screw hole formed thereon for receiving bolt224. When bolt 224 is fully tightened, front cover 223 clamps bearings232 and 236 and spacer 233 against base 221.

Alignment tool 200 further includes a ring 234 disposed between frontcover 223 and rotational body 222 and a ring 235 disposed betweenrotational body 222 and base 221. Rings 234 and 235 may be made ofrubber or other flexible or elastic material. When bolt 224 istightened, rings 234 and 235 are slightly compressed in the axialdirection. Rings 234 and 235 are configured to provide a proper amountof friction between respective components so that rotational body 222can be manually rotated and remain in position when the rotation forceis stopped.

Alignment tool 200 further includes an attaching mechanism 225 mountedonto back side 241 of base 221 via bolts 230 and washers 231. Attachingmechanism 225 may be a magnetic component, which includes the magneticmaterial described above and provides a magnetic force to securealignment tool 222 onto end face 237 of shaft 229. Attaching mechanism225 may have a disc shape, or any other appropriate shape. According toone embodiment, Attaching mechanism 225 may have a plurality of magneticpieces. For example, each magnetic piece may have a disc shape and bedisposed between the back side of base 221 and end face 237. Accordingto an alternative embodiment, attaching mechanism 225 and base 221 maybe formed as one piece. Accordingly, a portion of base 221 or entirebase 221 may be magnetized, and bolts 230 and washers 231 may beomitted. Still alternatively, attaching mechanism 225 may include asuction device, which provides a suction or vacuum force for attachingalignment tool 200 to end face 237. One skilled in the art willappreciate that other attaching mechanisms may also be used to attachalignment tool 200 to end face 237 of shaft 229.

Alignment tool 200 further includes one or more mounting elements, suchas rods 226 and 228. Rods 226 are inserted into respective grooves 242made on an exterior surface of rotational body 222, and secured torotational body 222 by bolts 227 tightened into a screw hole formed inrotational body 222. The screw hole for receiving bolt 227 is formedproximate to groove 242 so that a portion of bolt head of bolt 227 (oran associated washer) clamps rod 226 in a fixed location when bolt 227is tightened. Rod 228 may be mounted onto rotational body 221 through ascrew hole 239 formed on the exterior surface of rotational body 222.Rod 228 has a threaded end portion which is received by screw hole 239.

An alignment meter 245 may be mounted onto rods 226 or 228 forconducting a shaft alignment between shaft 229 and an opposite shaft.Alternatively or additionally, a dial gauge 246 may be mounted onto rods226 or rod 228 for aligning shaft 229 with the opposite shaft. Further,rods 226 and 228 may be used to rotate rotational body 222 during thealignment procedure.

During an alignment procedure, alignment tool 200 is first aligned withshaft 229 through, for example, a dial gauge 247 depicted in FIG. 4.Because of the alignment between alignment tool 200 and shaft 229,rotation of rotational body 221 is substantially equivalent to rotationof shaft 229 itself with respect to variations of shaft position andorientation. As a result, the rotation of rotational body 221 simulatesthe rotation of shaft 229 when the alignment procedure is carried out.Thus, the rotation of shaft 229 is not needed during a shaft-to-shaftalignment procedure.

Industrial Applicability

Alignment tools 100 and 200 described above may be used to perform anaxial alignment between two shafts in a variety of industrial ormechanical systems. For example, alignment tools 100 and 200 may be usedin a turbine system to align an output shaft 104 of a turbine engine andan input shaft 102 of a gear box as shown in FIG. 1. Further, alignmenttools 100 and 200 may be used to align an output shaft of any type ofpower system and a component to be driven by the power system. Evenfurther, the alignment tools 100 and 200 can be used to align any twoshafts that are intended to rotate together.

FIG. 6 illustrates a process 500 of axial alignment using alignment tool100 of FIGS. 2 and 3. According to process 500, at step 502, eachadjustable arm 2 is assembled by mounting roller assemblies 3 and 12 onthe second end section of adjustable arm 2.

At step 504, first end sections 25 of adjustable arms 2 are insertedinto respective grooves 19 on the back side of center hub 1. Theadjustable arms 2 are then coupled to the center hub 1 by bolts 5extending through slots 18. If the self-adjustment mechanism is providedfor adjustable arm 2, spring 35 is disposed into hole 31 of center hub 1before the adjustable arm 2 is inserted.

At step 506, alignment tool 100 is mounted onto shaft housing 8.Specifically, center hub 1 is first positioned at the center of bore 24.It is not required to position center hub 1 in alignment with shaft 9.Adjustable arms 2 are urged inwards or outwards along respective grooves19 to adjust the length of second end section 26, so as to place rollerassemblies 3 and 12 on front surface 23 and bore 24, respectively.

The length of second end section 26 of each adjustable arm 2 may beadjusted in a number of manners. According to one embodiment, forexample, if the self-adjustment mechanism described above isincorporated in every adjustable arm 2, the adjustable arms 2 may beadjusted by allowing spring 35 to urge adjustable arms 2 and pressroller assemblies 12 onto bore 24. As a result, minimum manualadjustments are required to properly position adjustable arms 2.

According to another embodiment, if the self-adjustment mechanism isincorporated in less than all of the adjustable arms 2, adjustable armor arms 2 without the self-adjustment mechanism are manually adjusted soas to press roller assemblies 3 and 12 onto front surface 23 and bore24. Bolts 5 corresponding to these adjustable arms 2 are then tightenedto fix the respective adjustable arms to center hub 1. Thereafter, theadjustable arm or arms 2 having the self-adjustment mechanismincorporated therein are adjusted so as to allow spring 35 to pushrespective adjustable arm 2 outwards and press roller assembly 12 onbore 24.

According to still another embodiment, none of adjustable arms 2 has theself-adjustment mechanism. As a result, the length of second end section26 of each adjustable arm 2 is manually adjustable so as to press theroller assemblies 3 and 12 onto front surface 23 and bore 24,respectively. Thereafter, bolts 5 corresponding to each adjustable arm 2is tightened to fix the adjustable arm 2 to center hub 2.

After all of the adjustable arms 2 are properly adjusted as describedabove, alignment tool 100 is mounted and attached to shaft housing 8through the radial force provided by the self-adjustment mechanism ormanual adjustment described above. When magnetic components 29 areprovided at the end of adjustable arms 2, the magnetic components 29provide magnetic forces to assist the mounting of alignment tool 100onto shaft housing 8.

At step 508, rod or rods 6 are inserted into respective groove orgrooves 22 of center hub 1. Bolt 7 is tightened to secure respective rod6 within groove 22.

At step 510, an alignment meter, such as a laser transmitter 10 and/or adial gauge 11, is mounted onto rod or rods 6, and an radial alignmentprocedure is carried out to align shaft 9 with opposite shaft 13 (FIG.2). For example, the laser transmitter 10 may transmit laser signals toa laser receiver mounted on opposite shaft 13, or a laser receiver maybe coupled to rod or rods 6 to receive laser signals from a lasertransmitter mounted on opposite shaft 13. Alignment tool 100 carryinglaser transmitter 10 is rotated either clockwise or counter clockwiseby, for example, 180 degrees with a 5-degree increment for each step.Alignment data are collected through the laser signals provided by lasertransmitter 10 at each step. Based on the alignment data, the relativeposition between shaft 9 and opposite shaft 13 may be adjusted asnecessary.

Additionally or alternatively, a dial gauge 11 may be mounted on rod 6via an extension arm 30. A tip of dial gauge 11 may be placed on variousparts associated with opposite shaft 13, such as the shaft itself or ahousing that is aligned with the shaft. The relative position betweenshaft 9 and opposite shaft 13 may be measured by rotating alignment tool100 with dial gauge 11 mounted thereon. Dial gauge 11 providesmeasurements for determining the relative position between the shafts.Alignment tool 100 may be rotated either clockwise or counter clockwiseby, for example, 180 degrees with a 5-degree increment for each step.Alignment data are collected from dial gauge 11 at each step. Based onthe alignment data, the relative position between shaft 9 and oppositeshaft 13 may be adjusted as necessary.

The steps of process 500 described above may be performed in a differentorder. For example, the step 504 may be performed before step 502. Andsimilarly, step 508 may be performed before step 502 or 504. Otherorders of the steps will be recognized by one skilled in the art uponreading this disclosure.

Alignment tool 100 provides easy mounting and dismounting of alignmenttool 100 by way of the adjustable arms 2 and magnetic components 29. Nobolts or screws are needed to secure alignment tool 100 onto shafthousing 8. Alignment tool 100 may be used on a machine housing cutout,such as the bore on a shaft housing 8 for a gear box, depicted in FIG.2. Alternatively, alignment tool 100 may be mounted across any openingof a structure where a conventional tool is difficult to mounted to acenter of the opening.

Alignment tool 100 may be easily rotated as necessary along the sidewall of bore 24 by roller assemblies 3 and 12 on the respectivesurfaces. The self-adjustment mechanism and the magnetic forces providedby the magnetic components allows alignment tool 100 to be secured toshaft housing 8, while allowing rotational movement of alignment tool100.

In addition, the self-adjustment mechanism of the arm or arms 2 apply acontinuous radial force onto each adjustable arm 2. The radial forceprovided by loaded spring 9 automatically adjusts the length of secondend section 26 of each adjustable arm 2 and allows roller assemblies 3and 12 to trace the variations of front surface 23 and bore 24. As aresult, the rotational movement of alignment tool 100 reflects theposition of shaft housing 8 and hence shaft 9.

Furthermore, alignment tool 100 allows for alignment of mechanicalsystems, in which shaft 9 is recessed within bore 24. Because of thelimited space within bore 24, it is difficult to mount conventionalalignment tools onto the end face of shaft 9 and rotate bulky alignmentmeters within bore 24. Alignment tool 100, on the other hand, allowsshaft 9 to be aligned with the opposite shaft through housing 8. Inparticular, shaft 9 and housing 8 are pre-aligned during assembly. As aresult, aligning housing 8 with opposite shaft 13 also ensures alignmentbetween shafts 9 and 13.

Further, the alignment meter can provide measurements of the relativeposition between shafts 9 and 13 regardless of the location of centerhub 1 with respect to shaft 9. This is achieved because adjustable arms2 support center hub 1 and maintain a fixed relative position betweenbore 24 and center hub 1. When alignment tool 100 is rotated, center hub1 and the alignment meter 10 or 11 mounted thereon trace a circulartrajectory that is substantially co-centered with bore 24 and shaft 9.As a result, rotating alignment tool 100 is substantially equivalent torotating shaft 9 itself, regardless of the location of center hub 1. Inaddition, because the rotation of alignment tool 100 substantiallyreplicates the rotation of shaft 9, the physical rotation of shaft 9 isnot needed for the alignment between shaft 9 and opposite shaft 13.

FIG. 7 illustrates a process 600 of axial alignment using alignment tool200 of FIGS. 4 and 5, according to one embodiment. According to process600, at step 602, magnetic component 225 is mounted onto the back sideof base 221 via bolts 230 and washers 231.

At step 604, rotational body 222 and rings 234 and 235 are mounted ontoshaft 238 of base 221 via bearings 232 and 236. Specifically, ring 235and bearing 236 are first mounted onto shaft 238, and spacer 233 is slidonto shaft 238 in front of bearing 236. Rotational body 222 is slid ontobearing 236 and spacer 233. Bearing 232 is then mounted onto shaft 238and disposed within a bearing housing on rotational body 222. Ring 234is placed on the end face of rotational body 222.

At step 606, front cover 223 is mounted onto the end face of shaft 238via bolt 224. Bolt 224 is tightened to secure front cover 223 onto shaft238, while allowing rotational body 222 to be rotatable between frontcover 223 and base 221.

At step 608, rods 226 and 228 are mounted onto rotational body 222.Specifically, rods 226 are inserted into respective grooves 242. Bolts227 are tightened to secure rods 226 within grooves 242. Rod 228 ismounted onto rotational body 222 by tightening the threaded section ofrod 228 into screw hole 239.

At step 610, assembled alignment tool 200 is mounted onto shaft 229 andan axial alignment is carried out to align shaft 229 and an oppositeshaft (not shown). Alignment tool 200 is mounted onto shaft 229 throughattaching mechanism 225. In one embodiment, attaching mechanism 225includes one or more magnetic components. Alignment tool 200 is mountedonto shaft 229 by bringing the magnetic component into contact with endface 237 of shaft 229. The magnetic force provided by the magneticcomponent attaches alignment tool 200 onto shaft 229. Alternatively,when attaching mechanism 225 includes a suction device, alignment tool200 is mounted onto shaft 229 by pressing the suction device onto endface 237. The suction force provided by the suction device securesalignment tool 200 onto end face 237.

After alignment tool 200 is secured, a radial alignment betweenalignment tool 200 and shaft 229 is first conducted through dial gauge247. As shown in FIG. 4, for example, dial gauge 247 is mounted on rod228, while a tip of dial gauge 247 is placed on the bore 250 of shafthousing 255. Rotational body 222 carrying dial gauge 247 is rotated tomeasure the relative radial position between alignment tool 200 and theshaft 255 bore. Based on the measurement provided by dial gauge 247,alignment tool 200 is adjusted so that it is aligned with the bore andhence shaft 229. Alternatively, the tip of dial gauge 247 is placed ontothe shaft body of shaft 229 itself. A similar radial alignment iscarried out to aligned alignment tool 200 with shaft 229.

Furthermore, an alignment meter, such as a laser transmitter 245 or adial gauge 246 described above, is mounted onto rods 226 and/or 228 foraligning shaft 229 with the opposite shaft. The alignment procedure issimilar to that describe above in connection with FIG. 6. During thealignment between shaft 229 and the opposite shaft, readings provided bydial gauge 247 are monitored to ensure that alignment tool 200 remainedaligned with shaft 229.

The steps of process 600 described above may also be performed in adifferent order. For example, step 608 may be performed before steps 602and/or 604. And similarly, base 221 including attaching mechanism 225may be first mounted onto shaft 229 before other components areassembled. Other orders for performing process 600 will be recognized byone skilled in the art upon reading this disclosure.

Alignment tool 200 may provide similar advantages as those of alignmenttool 100 described above. Specifically, attaching mechanism 225 provideseasy mounting and dismounting of alignment tool 200 onto front face 237of shaft 229 or any surfaces that require radial alignments.

Alignment tool 200 is particularly suitable for aligning shafts thatprotrude beyond the shaft housing. By rotating body 222, which carriesthe alignment meter, rotation of the shaft itself is not needed duringthe alignment procedure. As a result, alignment tool 200, similar toalignment tool 100, saves time and effort and prevents the shaft fromdamage during the alignment. Furthermore, when dial gauge 247 is placedon the bore to align alignment tool 200 with shaft 229, a pre-alignmentbetween shaft 229 and the bore is preferred. Alternatively, if dialgauge 247 is placed on shaft 229 itself to align alignment tool 200 withshaft 229, a pre-alignment between shaft 229 and the bore is not needed.

According to another embodiment, alignment tools 100 and 200 may be usedtogether or separately. For example, alignment tool 100 may be mountedonto gearbox housing 126, while alignment tool 200 may be mounted ontooutput shaft 104. As a result, shafts 102 and 104 may be aligned byaligning shaft 104 with gearbox housing 126. Alternatively, alignmenttool 100 may be mounted onto the opening of coupling hub 114, whilealignment tool 200 may be mounted onto output shaft 104 of the turbineengine. Thus, shafts 102 and 104 may be aligned through the alignmentbetween shaft 104 and coupling hub 114. Still alternatively, twoalignment tools 100 may be mounted onto the bores of gearbox housing 126and engine housing 128, respectively, so that shafts 102 and 104 may bealigned through the alignment between gearbox housing 126 and enginehousing 128. Still alternatively, two alignment tools 200 may berespectively mounted on shafts 102 and 104 or shaft connectors 112 and116, so that shafts 102 and 104 may be aligned by simulating theirrespective rotations through alignment tools 200.

Still alternatively, alignment tools 100 and 200 may be used inconjunction with conventional alignment tools for aligning shafts 102and 104. For example, alignment tool 100 may be mounted onto the bore ofgearbox housing 126 or the opening of coupling hub 114, while aconventional alignment tool may be mounted to shaft 104 or enginehousing 128. An axial alignment procedure may be carried out by rotatingalignment tool 100 to trace the bore of gearbox housing 126 or theopening of coupling hub 114. Alternatively, alignment tool 200 may bemounted onto shaft 102 or shaft connector 112, while a conventionalalignment tool may be mounted to shaft 104 or engine housing 128.Similarly, an axial alignment procedure may be carried out by rotatingalignment tool 200 to simulate the rotation of shaft 102. One skilled inthe art will appreciate that other variations and combinations ofalignment tools 100 and 200 may be implemented upon reading thedisclosure.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the disclosed shaftalignment tools. Other embodiments will be apparent to those skilled inthe art from consideration of the specification and practice of thedisclosed shaft alignment tools. It is intended that the specificationand examples be considered as exemplary only, with a true scope beingindicated by the following claims and their equivalents.

What is claimed is:
 1. A shaft alignment tool comprising: a baseincluding a shaft attaching mechanism for attaching the shaft alignmenttool to an end surface of a first shaft to be aligned with a secondshaft, the base further including a base shaft protruding axially fromthe base; a rotational body mounted on the base shaft of the basethrough one or more bearings for relative rotation with respect to thebase, wherein the rotational body is aligned co-axially with the firstshaft; and an alignment meter coupled to the rotational body forproviding alignment measurements between the first shaft and the secondshaft.
 2. The shaft alignment tool of claim 1, wherein the base includesa front side facing away from the end surface of the first shaft and aback side facing toward the end surface of the first shaft.
 3. The shaftalignment tool of claim 2, wherein the base shaft is disposed at acenter of the front side of the base.
 4. The shaft alignment tool ofclaim 1, wherein the shaft attaching mechanism is disposed on the backside of the base.
 5. The shaft alignment tool of claim 1, wherein theone or more bearings include a first bearing and a second bearingmounted on the base shaft, and the shaft alignment tool further includesa spacer mounted on the base shaft and between the first bearing and thesecond bearing for securing an axial distance between the first bearingand the second bearing.
 6. The shaft alignment tool of claim 1, whereinthe shaft attaching mechanism includes a magnet or suction deviceconfigured to couple the shaft alignment tool to a shaft.
 7. The shaftalignment tool of claim 1, wherein the alignment meter includes at leastone of a laser transmitter, laser receiver, or a dial gauge.
 8. Theshaft alignment tool of claim 7, wherein the alignment meter is coupledto the rotational body through at least one rod that extends radiallyfrom the rotational body.
 9. A method of aligning a first shaft and asecond shaft, the method comprising: coupling a shaft alignment tool toan end surface of the first shaft, wherein the alignment tool includes abase attached to the end surface of the first shaft through a shaftattaching mechanism, and a rotational body mounted on a base shaftprotruding axially from the base through one or more bearings; aligning,co-axially, the rotational body of the shaft alignment tool with thefirst shaft; rotating the rotational body; and performing the radialalignment between the first shaft and a second shaft based on therotating of the rotational body and using an alignment meter coupled tothe rotational body.
 10. The method of aligning of claim 9, wherein theperforming of the radial alignment includes rotating one of a lasertransmitter, laser receiver, or dial gage with the rotating of therotational body.
 11. The method of aligning of claim 9, furtherincluding coupling the alignment tool to the first shaft by one of amagnet or a suction device.
 12. The method of aligning of claim 9,wherein the aligning of the rotational body of the shaft alignment toolwith respect to the first shaft includes aligning the rotational body ofthe shaft alignment tool with respect to a housing bore aligned with thefirst shaft.
 13. The method of aligning of claim 9, further includingmaintaining the first shaft stationary during the rotating of therotational body.
 14. The method of aligning of claim 9, wherein thealignment tool further includes a front cover mounted to an end of thebase shaft for securing the rotational body to the base shaft, and themethod further includes adjusting the front cover to adjust frictionapplied to the rotational body.
 15. The method of aligning of claim 9,further including: rotating the rotational body with the alignment meterat incremental steps within a predetermined range of angle; recordingalignment data at each incremental step; and positioning the first shaftand the second shaft with respect to each other based on the alignmentdata.
 16. A shaft alignment tool comprising: a base having a base shaftextending normal with respect to a front side of the base, the baseincluding a shaft attaching mechanism for attaching the shaft alignmenttool to an end surface of a first shaft to be aligned with a secondshaft; a rotational body mounted on the base shaft through one or morebearings for relative rotation with respect to the base, wherein therotational body is aligned co-axially with the first shaft; at least onearm extending radially from the rotational body; and an alignment metercoupled to the at least one arm for providing alignment measurementsbetween the first shaft and the second shaft.
 17. The shaft alignmenttool of claim 16, wherein the one or more bearings include a firstbearing and a second bearing mounted on the base shaft, and the shaftalignment tool further includes a spacer mounted on the base shaft andbetween the first bearing and the second bearing for securing an axialdistance between the first bearing and the second bearing.
 18. The shaftalignment tool of claim 16, further including a magnet or suction deviceconfigured to couple the shaft alignment tool to the end surface of thefirst shaft.
 19. The shaft alignment tool of claim 16, wherein thealignment meter includes at least one of a laser transmitter, laserreceiver, or a dial gauge.
 20. The shaft alignment tool of claim 16,further including a front cover located at an end of the base shaftopposite the front side of the base.